Apparatus for automatically centering a moving object



April 17, 1962 H. c. MORROW 3,029,655

APPARATUS FOR AUTOMATICALLY CENTERING A MOVING OBJECT Filed Jan. 7, 1960 IN VE IV TOR HARRY C. MORROW Attorney 3,G29,655 APPARATUS FQRAUTGMATICALLY CENTERING A MOVING OBJECT Harry C. Morrow, Pittsburgh, Pa, assignor to United States Steel Corporation, a corporation of New Jersey Fiied Jan. 7, 1960, Ser. No. 1,010 2 Claims. (Cl. 74-441) Y companying adverse affect on the centering action of the roll.

It is therefore an object of my invention to provide relatively inexpensive apparatus for automatically centering a moving object, such as the return run of a belt conveyor, where the load on the roll is light.

Another object is to provide such apparatus in the form of a roll having a small area in contact with the object being conveyed.

These and other objects will be more apparent-after referring to the following specification and attached drawings, in which: 7

FIGURE 1 is a schematic elevation showing a belt conveyor utilizing my invention;

FIGURE 2 is a view, partly in section, showing the details of the roll of my invention; and

FIGURE 3 is an end view of the roll of FIGURE 2.

Referring more particularly to the drawings reference numerals 2 and 4- represent the head and tail pulleys around which a belt 6 passes. A return idler roll 8 bears against the lower run of the belt 6. It will be understood that the belt conveyor may be troughed instead of flat as shown and that more than one roll 8 may be used along the length of the return or lower run of the belt. According to my invention the roll 8 is constructed as shown in FIGURES 2 and 3 and includes a shaft 10 having a reduced diameter portion '12 at each end which is received in suitable bearings 14. The shaft 10 has a keyway 16 extending between the reduced diameter portions 12. A plurality of metal collars 18 are arranged in spaced apart relationship on the shaft 10 at each side of the transverse center thereof. A resilient disc 20, preferably made of rubber or rubber-like material, is attached to each of the collars 18. For this purpose several longitudinal slots 22 are provided in the collar 18 with the rubber of the disc '20 extending into the slots and being bonded thereto and to the outer surface of the collar. The flexible discs 20 are inclined radially away from the axis of the roll toward the transverse center thereof as shown in FIGURE 2. Each of the collars 18 has a keyway 24 therein which matches the keyway 16 in the shaft. A key 26 in the keyways l6 and 24 prevents rotation of the collars 18 and the resilient discs 20 with respect to the shaft. Preferably a separate key is provided for each collar 13. Two set screws 28, preferably spaced 90 apart, pass through threaded openings in each of the collars 18 and bear against the shaft 10 so as to prevent longitudinal moveil'nited States Patent ice merit of the metal collars 18. A metal collar 30 is preferably provided on the transverse center of the shaft H0 and has a keyway 32 therein for receiving a key 26. The construction of the collar 30 is substantially the same as that of collars 18 with set screws 34 being provided to prevent longitudinal movement thereof. A resilient disc 36 is attached to the collar 30 in the same manner as discs 20 are attached to their associated collars. However, the disc 36 is radial instead of being inclined in the manner of the other discs. The inclination of the discs 20 is preferably at an angle of 30 as shown. The distance between the discs is substantially greater than the thickness of the discs. For example, the thickness of the disc may be with the distance between the discs 20 on each side of the transverse center of the shaft being 3". "If the center disc 36 is provided, it, too, will be thick with a distance of 1- /2" between it and the disc 20 on either side thereof. The diameter of each of the discs is preferably substantially equal to the diameter of each of the other discs.

In operation, as the belt 6 passes over the discs 20 they will bend downwardly toward the axis of the shaft toward the transverse center thereof. Thus a force is created on the belt which has a component directed axially toward the transverse center of the belt. If the belt should move off the center of the roll toward the right side thereof there will be a greater total force on the belt to the right of the transverse center of the roll than on the remaining portion of the belt so that the belt will move to the left and again become centered when the two opposing forces are equal. If thejbelt should move to the left off the center of the roll there will be a greater force on the belt to the left of the transverse center than on the belt to the right of the transverse center of the roll so that the belt will move to the right to a centered position where the two opposing forces are in equilibrium.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. In a belt conveyor having head and tail pulleys over which the belt passes, an automatic self-centering return idler roll over which the lower run of the belt passes, said return idler roll comprising a shaft having a reduced diameter portion at each end thereof, said shaft having a keyway therein extending between said reduced diameter portions, a metal collar at approximately the transverse center of said shaft having a keyway therein matching the keyway in said shaft, a radial resilient disc attached to said metal collar, a plurality of metal collars spaced apart on said shaft at each side of the transverse center thereof, each of said last named collars having a keyway therein matching the keyway in said shaft, a resilient disc attached to each of said last named metal collars, each of saidlast named discs being inclined radially away from the axis of said shaft toward the transverse center thereof, the distance between said discs being substantially greater than the thickness thereof, means for locking said collars from axial movement on said shaft, and a key in said matching keyways preventing rotation of said collars on said shaft.

2. In a belt conveyor having head and tail pulleys over which the belt passes, an automatic self-centering return idler rollover which the lower run of the belt passes, said return idler roll comprising a shaft having a reduced diameter portion at each end thereof, said shaft having a keyway therein extending between said reduced diameter portions, a plurality of collars spaced apart on said shaft a key in said matching keyways preventing rotation of said collars on said shaft.

References Cited in the file of this patent at each side of the transverse center thereof, each of i said collars having a keyway therein matching the key- Way in said shaft, a resilient disc attached to each of said collars, each of said discs being inclined radially away from the axis of said shaft toward the transverse center thereof, the distance between said discs being substantially greater than the thickness thereof, means for locking said collars from axial movement on said shaft, and

UNITED STATES PATENTS Mallory Mar. 16, 1926 Kass Mar. 3, 1931 Weiss et a1. Aug. 15, 1939 Lorig Apr. 15, 1952 Lorig Apr. 15, 1952 Murphy Dec. 23, 1952 Lorig Nov. 24, 1953 Mursch et a1. 2 Oct. 25, 1955 

